Work table for stationary power-operated machine



WORK TABLE FOR STATIONARY POWER-OPERATED MACHINE Filed June 4, 1963 1| 27, 29 INVENTOR l||Ih CHRISTIAN B. ZIMMERMAN United States Patent Oiiice $2,535 Wi TABLE FR STATINARY PfVER-EERATED MACHlNE Christian li. Zimmerman, Lancaster, Pa., assigner, by

messie assignments, to "Ehe Black and Decker Manninoturing Company, rlawson, Md., a corporation ofA lv/iaryland Filed ,inne d, i963, Ser. No. 285,294 3 Claims. (Cl. 83-471) The present invent-ion relates to a fabricated work table ,for a stationary machine having a power-operated cutting tool supported from a radial arm, and more particularly, to a composite corrugated-aluminum work table for a radial arm saw machine utilized for metal-cutting purposes. l

The radial arm saw machine is a very versatile piece of shop equipment and can be used for a variety of purposes, such as cutting-olf all types of wood, metals, plastics Vand other materials. In the use of the machine as a cut-off saw, a saw carriage is traversed .along the stationary radial arm; and the saw carriage is provided with Ia power-operated circular saw blade, which, while cutting through the workpiece, is adapted to project partially within a kerf previously formed to a desired depth in the Work table. In the prior art, the Work table has usually been made of wood or a brous type of material, such that the blade itself can cut the desired kerf in the work table. When the radial arm saw machine is used for metal-cutting purposes, however, the peripheral portion ot the blade must entend'considerably below the top surface of the work table; otherwise, a frictional drag.will develop which results in a jagged or rough cut. Consequently, for metal cutting operations, the kerf in the work table should be formed t-o a greater depth than that which would ordinarily be required for cutting other materials; and thus for reasons of strength as well as economy, the wooden work table heretofore used in the pr-ior art is Vgenerally unsatisfactory. Besides, for metal-cutting operations, the circular blade is usually provided with a suitable coolant in the form of a mist or fluid, and the use of such coolants is generally not compatible with a work table made from a woodber material. On the other hand, if the work table were made of a solid piece of metal, such as aluminum, then it must be suniciently thick to provide adequate strength and stability against warpage after one or more kerfs are cut into it; and thus for reasons of economy of manufacture, the use of a solid metal work table is generally precluded.

Accordingly, it is an `object of the present invention to alleviate the aforementioned deficiencies of the prior art by providing a composite aluminum work table fabricated from one'or more corrugated sheets having a ser-ies of longitudinal substant-ially-uniiorm flutes.

It is another object of the present invention to provide, for use in conjunction with a radial arm saw machine adaptable for metal-cutting applications, a fabricated Work table which is sufficiently rigid and stable, Vhas an attractive appearance, and is quite economical and convenient to manufacture.

It is still another object of the present invention to provide a work table having a cellular structure, which, while maintaining good structural strength, allows the blade to extend to a depth of approximately 40% of the thickness of the Work table.

It is yet still another object of the present invention to provide a composite work table which combines maximurn strength and minimum weight with minimum cost of materials.

In accordance with the general teachings of the present invention, there is herein illustrated and described a work table comprising at least one corrugated sheet having a series of longitudinal flutes. A plate is secured on top of the sheet, and a longitudinal kerf is formed in the plate between an adjacent two of the longitudinal flutes. This kerf is substantially parallel to the pair of adjacent ilutes, `such .that the saw blade may project through the kerf intermedi-ately of the adjacent flutes and to a depth which approaches the thickness of the corrugated sheet.

In accordance with the more specific teachings of the present invention, there is herein illustrated and described for use in conjunction with Va radial arm saw machine adapted for metal cutting operations, a composite work table comprising a center plate and a first corrugated sheet secured on top of the center plate, the corrugated sheet having a series of substantially-uniform longitudinal utes. A second corrugated sheet, preferably being substantially-identical to the rst corrugated sheet and also having a series ofsubstantially-uniform longitudinal utes, is secured on the bottom of the center plate with its iutes beingjsubstantially aligned with the respective flutes of the rst corrugated sheet. A top plate is secured on top of the first corrugated sheet, and a bottom plate is secured on the bottom of the second corrugated sheet. The top plate and the bottom plate each has respective iianges formed at the sides and edges thereof with the flanges being nested together to form a completely closed table. At least one longitudinal kerf is formed in the top plate between an adjacent two of the longitudinal utes of the first corrugated sheet, such that the peripheral portion of a circular saw blade may project through the kerf intermediately of the two adjacent tintes. The depth to which the'blade may project through the kerf approaches the depth of the flutes on the rst corrugated sheet and is approximately forty percent of the overall thickness of the work table, which for metal-cutting operations, is quite .sufcient and provides a smooth, clean cut.

These and other objects of the present invention will become apparent from a reading of the following specification, taken in conjunction with theV enclosed drawings, in which:

FIGURE 1 is a perspective view of a conventional radial arm saw machine which is provided with the work table of the present invention;

FIGURE 2 is an enlarged section view taken along the 4lines 2f-2 of FIGURE 1, showing the beginning of the longitudinal flutes of the Vrespective corrugated sheets which are mounted on either side of a flat center plate, and further showing the manner in which the top and britt-om plates nest together to form an enclosed work ta le; Y

FIGURE 3 is an enlarged section view taken along the lines 3 3 of FIGURE 1, showing the manner in which the longitudinal kerf is formed in the top plate interme- `diately of an adjacent pair of flutes of the iirst corrugated sheet, and further showing how the peripheral portion of the circular saw blade may project into the kerf between the adjacent flutes;

FIGURE 4 is an enlarged section View taken along the lines 4 4 of FIGURE l, further showing the longitudinal kerf formed in the top plate;

FIGURE 5 is an enlarged front elevation of a fragmentary portion of the work table, showing a dimple which is formed on one of theV flanges of the top plate to locate the making of the longitudinal kerf .after the cornposite work table h-as been fabricated; and

FIGURE 6 -is an enlarged section View of the table top, showing its embossed surface.

With reference to FIGURE 1, there is illustrated a conventional radial arm saw machine l@ with which the teachings of the present invention may find more particular utility, although it will be appreciated that the Y teachings and essence of the present invention are not Patented July 6, 1965 I necessarily confined thereto, but rather are equally applicable to a wide variety of power-operated tools and devices. With this in mind, the radial arm saw machine it), comprises a rameill, a column base l2 secured to the frame, a post of column i3 supported in the column base, a stationary radial arm i4 mounted on the column 13, a crank lever i5 for raising the arm 14 to a desired height, a tool or saw carriage i5 supported from the radial arm 14 and monted on conventional tracks (not shown) in the arm, whereby the saw carriage 16 may be manually traversed along the length of the radial arm 14 by means of the handle 15a, a power-operated circular saw blade i7 (or other cutting tool) mounted on the carriage lo, a saw guard l, an anti-kickback protective device i9, and the fabricated work table of the present invention, being generally denoted by the numeral 2).

With reference to FIGURES l through 5, the work table 2S includes a substantially-hat center plate 21 to which a iirst corrugated sheet 22 is secured. The corfu-- gated sheet 22, which may be formed from aluminum or other suitable materials, is readily-available on the commercial market and comprises a series of substantiallyuniform longitudinal iiutes 23 equally-spaced with respect to each other. Preferably, but not necessarily, the rst corrugated sheet 22 is bonded to the center plate 2l by means of a suitable epoxy-based adhesive material at the bases 24 of its respecitve flutes 23. A second corrugated sheet 25 is provided, corresponding substantially to the iirst corrugated sheet 22, and likewise has a series of substantially-uniform longitudinal tlutes Zdequallyspaced with respect to each other; and its respective bases 2'7 are likewise bonded to the center plate 21, such that the iiutes 23 and 26 of the sheets 22 and 25, respectively, are substantially aligned with each other. A top plate 28 is bonded to the first corrugated sheet 22 at various places along the portions 23a of the flutes 23. A bottom plate 29 is likewise bonded in a preferred manner to the respective portions 2da of the tlutes 26. The top plate 23 has iianges 3) and 3l formed along its sides and edges, see FIGURES 2 and 4, while the bottom plate 29 likewise has respecitve flanges 32 and 33 formed along its sides and edges. The respective anges 3Q, 31 of the top plate 25 are adapted to nest or overlap, see FIGURE 2, with respect to the corresponding anges 32, 33 of the bottom plato 29, thereby providing an enclosed construction for the overall composite work table 2).

With further reference to FIGURES l, 3, and 5, a longitudinal kerf 34 is formed in the top plate 28 after the work table 2@ has been fully assembled. This may be done by a cutting operation subsequent to the assembly ot the work table and its installation on the radial arm saw machine 19. 'The longitudinal ker-f 34, see FIGURE 3, is formed in the top plate 2S between, and substantiallyparallel to, an adjacent two of the longitudinal utes 23 of the first corrugated sheet 22, such that the peripheral portion of the blade i7 may project through the kerf 34 intermediateely of the adjacent flutes 23 to a depth which approaches the depth of the flutes 23 on the rst corrugated sheet 22 and to a depth which is approximatelyforty percent of the overall thickness of the compositeV work table 2li. Preferably, a pair of longitudinal angle stileners 35, having a longitudinal bracing member 36 secured therebetween, are bonded to the underside of the top plate 2S prior to the bonding of the top plate 2S to the irst corrugated sheet 22. The location of the kerf 34 in the top plate 28 is determined by means of a dimple 37, see FIGURE 5, which denotes the location in which the longitudinal kerf 34 is to be made subsequent to the overall assembly of the table 2d.

Moreover, in addition to the kerf 34, one or more auxiliary kerts 3S may be formed in the work table 2@ transversely of the corrugated sheet 22, so as t-o facilitate the making of a miter cut.

With reference to FIGURE 6, the top plate 25 may be provided with an embossed top surface so as to provide an attractive appearance and prevent the. work table 26 from being scratched or otherwise marred.

The composite work table 2b of the present invention is fully-enclosed (save for the kerf 34) and combines the desirable features and advantages or low cost and ease of assembly together with high strength, good stability, and minimum weight. The corrugated sheets 22 and 2S, having a wavy cross-section, facilitate a table having a ccliular structure. 'The embossed top finish of the table renders a pleasing, attractive appearance and prevents the table from being marred or scratched.

Obviously, many modications may be mad-e without departing from the basic spirit of the present invention; and accordingly, within the scope of 'the appended claims, the invention may be practiced other than has been specically described herein.

I claim:

A work table for a radial arm saw machine in which a motor-driven saw blade is traversed above the table; said work table comprising:

(A) a corrugated sheet having a series Vof longitudinal iutes, said tintes being arranged substantially parallel to the direction in which the saw blade is traversed above the table;

(B) a plate secured on top of said corrugated sheet, whereby a substantially-flat surface is provided for supporting a workpiece; and

(C) a longitudinal kerf fonned in said plate in substantial alinernent with the traversing saw blade;

(D) said longitudinal kerf being formed between an adjacent pair of said longitudinal iiutes in said cor-- rugated sheet;

(E) whereby the saw blade projects through said longitudinal kerf between said adjacent flutes to a predetermined depth bel-ow said plate;

(F) whereby a smaller arcuate portion of the saw blade is in engagement with the workpiece at any one time; and

(G) whereby a frictional drag on the blade is precluded and a cleaner cut is obtained, especially on metal-cutting operations.

2. A work table according to claim 1, wherein:

(A) the blade projects through said longitudinal kerf to a majority of the height of said adjacent pair of longitudinal flutes. Y

3. A work table according to claim 1, wherein:

(A) a pair of longitudinal angle stifeners are secured Vto theundersurface of said top plate, one on each side of said longitudinal kerf.

Reterences Cited by the Examiner UNITED STATES PATENTS 2,042,721 6/36 Loewy.

2,823,460 2/58 Weiler 269-289 2,989,145 6/61 Goodloe.

3,013,641 12/61 Compton.

ANDREW R. IUHASZ, Primary Examinez'. 

1. A WORK TABLE FOR A RADIAL ARM SAW MACHINE IN WHICH A MOTOR-DRIVEN SAW BLADE IS TRAVERSED ABOVE THE TABLE; SAID WORK TABLE COMPRISING: (A) A CORRUGATED SHEET HAVING A SERIES OF LONGITUDINAL FLUTES, SAID FLUTES BEING ARRANGED SUBSTANTIALLY PARALLEL TO THE DIRECTION IN WHICH THE SAW BLADE IS TRAVERSED ABOVE THE TABLE; (B) A PLATE SECURED ON TOP OF SAID CORRUGATED SHEET, WHEREBY A SUBSTANTIALLY-FLAT SURFACE IS PROVIDED FOR SUPPORTING A WORKPIECE; AND (C) A LONGITUDINAL KERF FORMED IN SAID PLATE IN SUBSTANTIAL ALINEMENT WITH THE TRAVERSING SAW BLADE; (D) SAID LONGITUDINAL KERF BEING FORMED BETWEEN AN ADJACENT PAIR OF SAID LONGITUDINAL FLUTES IN SAID CORRUGATED SHEET; (E) WHEREBY THE SAW BLADE PROJECTSTHROUGH SAID LONGITUDINAL KERF BETWEEN SAID ADJACENT FLUTES TO A PREDETERMINED DEPTH BELOW SAID PLATE; (F) WHEREBY A SMALLER ARCUATE PORION OF THE SAW BLADE IS IN ENGAGEMENT WITH THE WORKPIECE AT ANY ONE TIME; AND (G) WHEREBY A FRICTIONAL "DRAG" ON THE BLADE IS PRECLUDED AND A CLEANER CUT IS OBTAINED, ESPECIALLY ON METAL-CUTTING OPERATIONS. 